20857199 has 4 divisors (see below), whose sum is σ = 22753320. Its totient is φ = 18961080.

The previous prime is 20857183. The next prime is 20857211. The reversal of 20857199 is 99175802.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20857199 - 2⁴ = 20857183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20857099) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 948044 + ... + 948065.

It is an arithmetic number, because the mean of its divisors is an integer number (5688330).

Almost surely, 2^20857199 is an apocalyptic number.

20857199 is a deficient number, since it is larger than the sum of its proper divisors (1896121).

20857199 is a wasteful number, since it uses less digits than its factorization.

20857199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1896120.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 20857199 is about 4566.9682503823. The cubic root of 20857199 is about 275.2656342390.

The spelling of 20857199 in words is "twenty million, eight hundred fifty-seven thousand, one hundred ninety-nine".